Is there a way to add a custom action to the predefined all contacts view???

Is there a way to add a custom action to the predefined all contacts view???

Hello,

I need to synchronize data selected by the user (single or multiple) in the contacts view to my database using a web service.
So i need to add a custom action or a button if possible.Is it possible to add a custom action to a predefined view(e.g. Contacts view) ???

If not please suggest me some workaround for it...

Thanks